Muscle growth in crustacean is a complicated process where the muscle grows and develops through muscle restoration, and the growth rate depends on the net muscle gain during molting. Myostatin (MSTN) is a conserved inhibitor of muscle growth in vertebrates, but until now solid evidence supporting a similar function of MSTN in invertebrates has been lacking. In this study, we identified and characterized MSTN from the shrimp Exopalaemon carinicauda (EcMSTN) to better understand its biological function. The full-length cDNA of EcMSTN was 1,518 bp, encoding 428 amino acid residues, and the genomic sequence was 1,851 bp, including three exons and two introns. EcMSTN was expressed in a wide range of tissues, but predominantly detected in the abdominal muscle (P < 0.05). Low expression was detected in the cleavage, blastula and gastrula stages in the early development stages, increasing after the nauplius stage. EcMSTN expression was negatively correlated with the growth traits. After EcMSTN knockdown using RNA interference, EcMSTN expression was down-regulated in the abdominal muscle and up-regulated the expression of growth-related genes, including fast myosin heavy chain and skeletal muscle actin 3. After inhibiting EcMSTN for 5 weeks, the RNAi-treated shrimp with reduced EcMSTN levels exhibited a dramatically higher body weight compared with that of the control group. Association analysis revealed that two SNP loci g.Mstn220 and g.Mstn567 were markedly associated with both body weight and body length. The results would clarify the negative role of EcMSTN in regulating muscle growth during the intermolt stage and provide growth-related markers for molecular marker assisted breeding of E. carinicauda.

甲壳动物的肌肉生长是一个复杂的过程，肌肉通过肌肉恢复而生长和发育，生长速度取决于蜕皮期间的净肌肉增益。肌肉生长抑制素 (MSTN) 是脊椎动物肌肉生长的保守抑制剂，但直到现在还缺乏支持 MSTN 在无脊椎动物中具有类似功能的确凿证据。在这项研究中，我们从虾Exopalaemon carinicauda ( EcMSTN ) 中鉴定并表征了MSTN ，以更好地了解其生物学功能。EcMSTN的全长cDNA为1,518 bp，编码428个氨基酸残基，基因组序列为1,851 bp，包括3个外显子和2个内含子。电子商务网在广泛的组织中表达，但主要在腹肌中检测到（P  <0.05）。在早期发育阶段的卵裂、囊胚和原肠胚阶段检测到低表达，在无节幼体阶段后增加。EcMSTN表达与生长性状呈负相关。使用 RNA 干扰敲除 EcMSTN 后，EcMSTN 在腹肌中的表达下调，并上调生长相关基因的表达，包括快速肌球蛋白重链和骨骼肌肌动蛋白 3。抑制EcMSTN 5 周后， RNAi-减少EcMSTN的处理过的虾与对照组相比，水平显示出显着更高的体重。关联分析显示，两个 SNP 基因座 g.Mstn220 和 g.Mstn567 与体重和体长均显着相关。研究结果将阐明EcMSTN在蜕皮期调节肌肉生长的负面作用，并为E. carinicauda分子标记辅助育种提供生长相关标记。